Aconitum napellus, also known as aconite, monkshood and wolfsbane, has been cultivated in gardens for centuries. It's a stately plant with stunning flowers and carries a long and fascinating history. Before planting aconitum, you would be wise to learn about it and follow a few precautions.
Aconitum napellus is a shade-loving hardy perennial and member of the buttercup family. It is native to mountainous parts of the Northern Hemisphere. The dark green, glossy leaves are deeply divided and are a welcome sight in the spring because they are among the first to emerge. The 2- to 4-foot plant sends up spikes of showy blue-violet flowers in July and August. The name "monkshood" derives from the shape of the flowers, which look like blue helmets. The fleshy root is pale when young, but matures to a dark brown. The root contains a poisonous alkaloid, and all parts of the plant are dangerous if ingested.
Aconitum prefers moist organic soil and does best in partial shade. It will not do well in a hot, dry or sunny area. Propagate by dividing the roots in the fall. Plants are slow to establish, so it is best not to divide for several years. If you deadhead the plant, you may get a second flowering. Leave the basal growth through the winter, cutting it back in the spring. Aconitum can be cut back early in the season to control its height. This will result in sturdier plants. Even so, the taller varieties will probably require staking.
Aconitum is a valuable garden specimen since the flowers are long-lasting, and the plant is one of the few tall perennials that thrive in shade. Unsurprisingly for a poisonous plant, rabbits and deer do not bother it.
The Anglo-Saxons called this plant "thung", which was a general name for any poisonous plant. It was also called "wolfsbane" because of its use in mixtures for poisoning wolves. In Asia it was used to make poison arrows. In medieval times, it was considered a "witches' herb" because it was reputedly made into an ointment which allowed the user to fly.
Despite its reputation as a poison, aconitum was traditionally used in Western medicine as an anesthetic. It has been replaced by safer drugs. It is still used in very small amounts in traditional Chinese medicine for Yang deficiency, or energy depletion.
Aconitum in Literature
Aconitum is mentioned in Greek mythology, where it was said to have been invented by Hecate from the foam of Cerberus, and it was supposed to be in the cup of poison which Medea served to Theseus. One of the Brother Cadfael books, a series of historical murder mysteries set in an English monastery, features aconitum used as a poison. Wolfsbane is among the real plants mentioned in a fictional setting in the Harry Potter books (Hogwarts students learn it protects the user during werewolf transformation).
Aconitum henryi 'Spark's Variety' is a stately plant that grows 4 to 5 feet tall; it requires staking to stand tall. Aconitum carmichaelii 'Arendsii' is one of the few late-flowering perennials with blue flowers, and requires no staking because of its strong stems. Aconitum 'Eleanor' has beautiful bi-color flowers of white with a violet outline and is relatively compact at 36-40 inches.
Some short aconitum varieties that will not require staking are the 2 1/2- to 3-foot-tall Aconitum x cammarum 'Bressingham Spire', and the 2-foot-tall Aconitum septentrionale 'Ivorine', which has cream flowers.
The juice of the aconitum is a deadly poison. Always wear gloves when handling any part of this plant, particularly the roots. Take care not to get juice from the plant in your mouth or on any open wounds. Wash your hands immediately after handling. This plant should be considered for its ornamental value only and should never be planted near food plants. Do not cut the plant to bring inside, particularly where there are children or pets. It is not recommended for a garden where children may play.